Some communication networks use concatenation and encapsulation methods for transporting cells or other data frames. In these methods, multiple cells or frames are encapsulated and transported over the network using a transport protocol. The concatenation process reduces the overhead associated with adding headers to the individual data packets, relieves the network nodes of the task of individually processing each data packet and, provides functions such as end-to-end connectivity, Quality-of-Service (QoS) and protection.
For example, Asynchronous Transfer Mode (ATM) cells are sometimes encapsulated and transported using the Multiprotocol Label Switching (MPLS) protocol. MPLS is described in detail by Rosen et al., in Request for Comments (RFC) 3031 of the Internet Engineering Task Force (IETF), entitled “Multiprotocol Label Switching Architecture” (January, 2001), which is incorporated herein by reference. This reference is available at www.ietf.org/rfc. Methods for encapsulating ATM cells in MPLS packets are described by Martini et al., in an IETF Internet Draft entitled “Encapsulation Methods for Transport of ATM Over MPLS Networks,” May, 2006, which is incorporated herein by reference. This document is available at www.ietf.org/internet-drafts/draft-ietf-pwe3-atm-encap-11.txt.
In some cases, the encapsulated packets are transported over ring networks, such as Resilient Packet Ring (RPR) networks, as defined by the IEEE 802.17 working group. Applicable standards and additional details regarding RPR networks are available at www.ieee802.org/17.